The present invention relates to an optical switch employing a controlled ferroelectric, light permeable ceramic provided with electrodes, which is arranged between a polarizer and an analyzer.
Such an optical switch is disclosed in "Transparente Keramik fur die Optik", FUNKSCHAU 1975, No. 19, page 605. With the conventional optical switch in which PZT (transparent lead zirconate titanate) is used as the ferroelectric ceramic, the electrodes for controlling the double refraction of the ferroelectric ceramic are deposited in an interleaved form (interdigitated comb structures) directly onto the surface of the ceramic disk.
The setup of the conventional type of optical switch, as well as the arrangement of the electrodes directly upon the ceramic disk, have disadvantages which make it impossible to manufacture such types of optical switches for certain applications. Because of the unfavorable surface properties of the ferroelectric ceramic disk it is difficult to deposit electrodes having a good adherence to the ceramic for a sufficiently long period of time. Moreover, since the ceramic disks can only be manufactured with a reasonable expenditure and, consequently, economically up to a certain size (e.g. up to 10 cm .phi.), it is not possible to manufacture optical switches of the conventional type having a length of e.g. 20 cm and more.
It is therefore the object of the present invention to improve the aforementioned type of optical switch in such a way that it can be easily manufactured economically to have larger dimensions.